Ruminating over past stresses can lead to higher blood pressure, later health effects

Irvine, Calif. -- Which has the greatest effect on your heart's health: arguing with a spouse or running a marathon? Arguing could have closer links to later heart disease, but for an unusual reason. Just thinking about the fight appears to lead to high blood pressure and later health problems, according to a UC Irvine-led study.

Both tasks raise blood pressure and cause some stress on the body, but arguments have an emotional side that creates longer recovery times in the body than non-emotional -- yet stressful -- events like running. The study appears in the Sept./Oct. issue of Psychosomatic Medicine.

Laura Glynn, UCI assistant professor of psychiatry, and her colleagues at UC San Diego and Mount Sinai Medical Center in New York found that when asked to remember tasks associated with emotionally driven rises in blood pressure, students' blood pressure rose and stayed high. Thinking back to physical tasks did not have the same effect.

"Exposure to emotional stress may be of greater potential harm to cardiovascular health than stresses that lack emotion, even though both types of stress may have provoked the same initial responses," Glynn said. "Preventing the damaging effects of stress may involve not only reducing exposure to stressors, but also reducing opportunities to ruminate over past stress."

Glynn and her team tested 72 students at UC San Diego. Those who were asked to either count backwards while being interrupted or avoid an electric shock had higher systolic blood pressures (the upper number) by about 16 mm of mercury when asked to remember the tasks. By comparison, students who were told to walk in place or put their hands in freezing water had no increase in blood pressure when asked to remember the event. The blood pressures of students taking part in the first two emotional tasks took much longer to recover to normal levels.

In addition, another group of students who were left alone after an emotional task tended to ruminate over the task and have higher blood pressure than students who were distracted from thinking about the task. While the difficulty of the task played no role in determining later blood pressures, those who experienced fear and nervousness during the test were able to clearly recall those emotions and re-create their cardiovascular response.

Chronic stress is considered an important factor in elevation of blood pressure, which is considered a major cause of heart disease. While many researchers have looked at the role played by relentless chronic stress, such as a demanding job or unstable home life, relatively few studies have focused on the lingering effects of even a single, emotion-laden stressful event.

High blood pressure affects at least 20 percent of all Americans. Chronically high blood pressure, a condition known as hypertension, can lead to heart attacks, atherosclerosis, strokes and kidney failure.

"Our study indicates that certain people may be at increased risk for developing heart disease, based at least partly on how they respond to stress," Glynn said. "Developing ways to intervene with rumination behavior and encouraging social support for these individuals may help prevent emotional stress from contributing to heart disease later."

Glynn and her colleagues have been studying how stress may lead to a number of disorders, including premature birth, neurological disorders and cardiovascular disease.